This is literally what I'm doing atm, on my first non-basic-bigfixing issue at a new company. Something that should have take two days has taken three, going on

This is literally what I'm doing atm, on my first non-basic-bigfixing issue at a new company. Something that should have take two days has taken three, going on four weeks, I feel like a shitbag fraud for not polishing it off in two days (due to.pain time refactoring and seperating concerns). Noone can give me advice because <particular deity> left the company, and anyway they're rebuilding everything in <internal JS framework with no external deps>, but this critical feature needs to be done in place. Been in this situation before as well, thought I'd managed to escape...